#include <iostream>
using namespace std;
int main(){
int n, x;
cin >> n >> x;
int array[n];
for (int i = 0; i < n; i++){
cin >> array[i];
}
for (int i = 0; i < n; i++){
for (int j = 1; j <= n; j++) {
if ((array[i] + array[j]) == x) {
cout << "YES";
return 0;
}
}
}
cout << "NO";
return 0;